GENERAL INFORMATION

This README.txt file was updated on 2026-03-18
A. Paper associated with this archive
Citation: Liguori A., S. Korm, A. Profetto, E. Richters, and K. E. Gribble. 2026. Transgenerational and intergenerational maternal age effects exhibit genotype-specific, complex patterns of inheritance. The American Naturalist

Brief abstract: Maternal age effects, in which offspring phenotype is determined by a mother�s age at the time of birth, are common and variable among diverse taxa, but relatively little is known about their dynamics across multiple generations. Characterizing patterns of inter- and trans-generational inheritance of maternal age can provide insight into potential molecular and evolutionary mechanisms. In two strains of the rotifer Brachionus manjavacas, we maintained young and old maternal age lineages and tested whether maternal age effects on lifespan and reproduction changed in magnitude or direction across three generations. In the third generation, we initiated switched maternal age cohorts to achieve factorial combinations of maternal and grandmaternal ages to test for the reversibility of maternal age effects. For both strains, maternal age effects on lifetime reproductive output were consistent across generations, with no evidence for the accumulation of either positive or negative effects across old and young lineages. In one strain, offspring with older mothers had reduced lifespan, but the magnitude of this maternal age effect declined across generations. Switched maternal age cohorts revealed that effects were reversible within one generation, but only for certain response metrics and in a strain-dependent manner. Given the non-cumulative and often reversible nature of the maternal age effects observed here, we hypothesize that dynamic epigenetic and/or mitochondrial mechanisms are more likely to be involved than are changes to maternal provisioning or mutation accumulation.

B. Originators
Alyssa Liguori [1,2], Sovannarith Korm [1], Alex Profetto [1], Emily Richters [1], Kristin E. Gribble [1]
[1] Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543
[2] Department of Biology, State University of New York at New Paltz, New Paltz, NY 12561

C. Contact information
Alyssa Liguori
State University of New York at New Paltz, 1 Hawk Drive, New Paltz, NY 12561
liguoria@newpaltz.edu

D. Dates of data collection
March 2021 - October 2021

E. Geographic Location(s) of data collection
Woods Hole, MA, USA

F. Funding Sources
This work was funded by NSF CAREER Award IOS-1942606 and by NIA R01AG076592 to K. Gribble.ACCESS INFORMATION

1. Licenses/restrictions placed on the data or code
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
2. Data derived from other sources
N/A
3. Recommended citation for this data/code archive
Liguori A., S. Korm, A. Profetto, E. Richters, and K. E. Gribble. 2026. Data from: Transgenerational and intergenerational maternal age effects exhibit genotype-specific, complex patterns of inheritance. The American Naturalist. Harvard Dataverse.DATA & CODE FILE OVERVIEW
This data repository consist of 8 data files, 2 code scripts, and this README document, with the following data and code filenames and variables:

Data files and variables�survival_L5.csv� and �survival_RUS.csv� contain survivorship data over time (both files have the same format). �survival_L5.csv� contains data for the BmanL5 strain of Brachionus manjavacas, �survival_RUS.csv� contains data for the BmanRUS strain.There is a numbered column for each day of the experiment, and each row contains data for a single individual.�1� indicates that the individual was alive on that day�0� indicates that the individual was dead on that day�NA� indicates that the individual was lost, due to issue with transferring, or other mistakes (we do not know the survivorship status)The �censor� column indicates whether or not the event of interest (death) occurred within the experiment timeframe. �1� indicates that death was observed, �0� indicates that death was not observed, therefore that individual is censored.Variables include:�generation� : F0, F1, F2, F3 (in the manuscript, these generations are described as G0-G3)�line� : young_mother and old_mother (does not apply to the F0 generation)�switched_age� : N or Y (no or yes)Switched maternal age cohorts were initiated in the third generation, these cohorts have a Y: offspring were collected from the old maternal age lineage when mothers were young, and from the young maternal age lineage when mothers were old. �plate� : plate number�well� : well label (together with the plate number, forms the individual rotifer ID/location in the well plate)�neonates_L5.csv� and �neonates_RUS.csv� contain the number of neonates produced per individual, per day, over time (both files have the same format). �neonates_L5.csv� contains data for the BmanL5 strain of Brachionus manjavacas, �neonates_RUS.csv� contains data for the BmanRUS strain.These files have the same general format as the survival data files described above. They also have the same �censor� column.Numeric values are counts of neonates produced per day.�NA� indicates that neonate production could not be observed, either because the individual had died, or was lost.�rep_period_L5.csv� and �rep_period_RUS.csv� contain reproductive status data of mothers over time (both files have the same format). �rep_period_L5.csv� contains data for the BmanL5 strain of Brachionus manjavacas, �rep_period_RUS.csv� contains data for the BmanRUS strain.These files have the same general format as the survival data files described above. They also have the same �censor� column.�1� indicates that the individual was bearing eggs on that day�0� indicates that the individual was not bearing eggs on that day�NA� indicates that egg-bearing status could not be observed, either because the individual had died, or was lost.

'neonate_origins_L5_matriline.csv' and 'neonate_origins_RUS_matriline.csv' contain the identities of mothers for every individual rotifer in the experiments and the matriline that each individual was a part of. Matriline identity was tracked across generations, starting with F0 (G0) individuals. 'neonate_origins_L5_matriline.csv' contains data for the BmanL5 strain of Brachionus manjavacas, 'neonate_origins_RUS_matriline.csv' contains data for the BmanRUS strain. Each row contains data for a single individual. Both files have the same general format.

Variables include:�generation� : F1, F2, F3 (in the manuscript, these generations are described as G1-G3)

�line� : young_mother and old_mother (does not apply to the F0 generation)�switched_age� : N or Y (no or yes)Switched maternal age cohorts were initiated in the third generation, these cohorts have a Y: offspring were collected from the old maternal age lineage when mothers were young, and from the young maternal age lineage when mothers were old. �plate� : plate number
�well� : well label (together with the plate number, forms the individual rotifer ID/location in the well plate)

'gen_origin' : F0, F1, F2 (in the manuscript, these generations are described as G0-G2) This is the generation of the individual's mother.

'line_origin' : young_mother and old_mother (does not apply to the F0 generation) This is the maternal age line of the individual's mother.

'plate_origin' : plate number of the individual's mother

'well_origin' : well label of the individual's mother (together with the plate origin number, forms the mother's ID)

'strain' : L5 or RUS

'matriline' : each number represents an independent matriline that was initiated in the F0 (G0) generation. Matrilines were tracked across generations throughout the course of experiments - the matriline number of a rotifer was passed to her clonal offspring. Within a generation, individuals that share a matriline number are clonal siblings.Code scripts�Q1_across_gens.R� is an R script that conducts statistical analyses and generates all figures for Question 1 in the manuscript (Do maternal age effects differ in magnitude or direction across generations?)�Q2_Gen3.R� is an R script that conducts statistical analyses and generates all figures for Question 2 in the manuscript (Are maternal age effects reversible within one generation?)

SOFTWARE VERSIONS

R version 4.3.1 (2023-06-16)
Platform: x86_64-apple-darwin20 (64-bit)
Running under: macOS Sonoma 14.5

Package versions:
 [1] performance_0.15.0 lme4_1.1-34        Matrix_1.6-1.1     MASS_7.3-60        emmeans_1.8.9     
 [6] car_3.1-2          carData_3.0-5      survminer_0.4.9    ggpubr_0.6.0       survival_3.5-5    
[11] reshape2_1.4.4     lubridate_1.9.3    forcats_1.0.0      stringr_1.5.0      dplyr_1.1.3       
[16] purrr_1.0.2        readr_2.1.4        tidyr_1.3.0        tibble_3.2.1       ggplot2_3.4.3     
[21] tidyverse_2.0.0